1. Field of the Invention
This invention relates generally to adhesives and, more specifically, to a new adhesive which enables flocked, flexible articles, for example rubber profiles flocked with fibers, to be produced to higher quality standards.
2. Description of the Prior Art
It is known that vulcanized or unvulcanized elastomers or other plastic surfaces can be coated with a layer of adhesive and that short staple fibers can be applied perpendicularly thereof in an electrical field. The electrostatically flocked articles thus produced are distinguished by a fabric-like surface and, in many cases, by relatively low friction, for example with respect to glass. One of the many applications of these products is their installation as sealing sleeves in window compartments of automobiles.
To produce flocked, flexible articles of this type, it was proposed in German Pat. No. 29 16 909 to use a two-component adhesive of the reaction product of (meth)-acrylic acid and epoxidized polymers on the one hand and a compound containing amino groups on the other hand in conjunction with radiationhardening additives. With epoxy adhesives such as these, however, it is only possible to obtain minimal strengths on apolar elastomers, with the result that, in the event of mechanical stressing of the type encountered, for example, in the window compartments of automobiles during opening and closing of the windows, the flocks soon become detached from the adhesive layer. Accordingly, German Pat. No. 30 11 438 proposes using a primer together with an epoxy adhesive for flocking an apolar elastomer. The primer used is a solution of a chlorinated amorphous polypropylene in toluene. Although better results may possibly be obtained in this way, the procedure involved is relatively complicated.
Japanese Patent Applications No. 78 136 079 describes a process for flocking mixtures of ethylene-propylenediene terpolymers (EPDM) with an OH-functional butadiene elastomer using a polyurethane adhesive. However, even in the case of completely apolar elastomers, i.e. for example pure EPDM-elastomers, the proposed adhesive is unsuitable for producing abrasion-resistant flocked finishes, as required in practice.